diff --git a/.changeset/seven-years-knock.md b/.changeset/seven-years-knock.md
new file mode 100644
index 00000000..ca047d79
--- /dev/null
+++ b/.changeset/seven-years-knock.md
@@ -0,0 +1,6 @@
+---
+'@flatfile/configure': patch
+'@flatfile/listener': patch
+---
+
+Remove fallback to localhost
diff --git a/package-lock.json b/package-lock.json
index 0f272421..45f49db8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -37451,7 +37451,7 @@
     },
     "packages/javascript": {
       "name": "@flatfile/javascript",
-      "version": "1.5.1",
+      "version": "1.5.2",
       "license": "ISC",
       "dependencies": {
         "@flatfile/embedded-utils": "^1.3.4",
diff --git a/packages/configure/src/utils/authenticated.client.ts b/packages/configure/src/utils/authenticated.client.ts
index 6e08a9ef..252e6ca4 100644
--- a/packages/configure/src/utils/authenticated.client.ts
+++ b/packages/configure/src/utils/authenticated.client.ts
@@ -3,7 +3,7 @@ import { Configuration, DefaultApi } from '@flatfile/api'
 import fetch, { RequestInit } from 'node-fetch'
 
 const FLATFILE_API_URL =
-  process.env.AGENT_INTERNAL_URL || 'http://localhost:3000'
+  process.env.AGENT_INTERNAL_URL ?? 'https://platform.flatfile.com/api'
 
 export class AuthenticatedClient {
   private _api?: DefaultApi
@@ -37,6 +37,9 @@ export class AuthenticatedClient {
       'x-disable-hooks': 'true',
       ...options.headers,
     }
+    if (FLATFILE_API_URL == null) {
+      throw new Error('AGENT_INTERNAL_URL must be set in the environment')
+    }
     const fetchUrl = FLATFILE_API_URL + '/' + url
 
     return fetch(fetchUrl, {
diff --git a/packages/listener/src/events/authenticated.client.ts b/packages/listener/src/events/authenticated.client.ts
index 6d994acc..2f30db38 100644
--- a/packages/listener/src/events/authenticated.client.ts
+++ b/packages/listener/src/events/authenticated.client.ts
@@ -8,15 +8,17 @@ export class AuthenticatedClient {
 
   constructor(accessToken?: string, apiUrl?: string) {
     const FLATFILE_API_URL =
-      CrossEnvConfig.get('AGENT_INTERNAL_URL') || 'http://localhost:3000'
+      CrossEnvConfig.get('AGENT_INTERNAL_URL') ??
+      apiUrl ??
+      'https://platform.flatfile.com/api'
+
     const bearerToken = CrossEnvConfig.get('FLATFILE_BEARER_TOKEN')
 
-    this._accessToken = accessToken || bearerToken || '...'
+    this._accessToken = accessToken ?? bearerToken ?? '...'
 
-    this._apiUrl =
-      apiUrl || FLATFILE_API_URL
-        ? ensureSingleTrailingSlash(apiUrl || FLATFILE_API_URL)
-        : undefined
+    this._apiUrl = FLATFILE_API_URL
+      ? ensureSingleTrailingSlash(FLATFILE_API_URL)
+      : undefined
   }
 
   async fetch(url: string, options?: any) {
diff --git a/packages/listener/src/events/event.handler.spec.ts b/packages/listener/src/events/event.handler.spec.ts
index 8eb31205..d5b1f7d2 100644
--- a/packages/listener/src/events/event.handler.spec.ts
+++ b/packages/listener/src/events/event.handler.spec.ts
@@ -1,3 +1,4 @@
+import { CrossEnvConfig } from '@flatfile/cross-env-config'
 import { EventHandler } from './event.handler'
 
 describe('EventHandler', () => {